spicebird98

iTrader: (10)

I've got a set of milled 241's ready to go on my stock ls1 shortblock. Will be keeping the stock cam. Am i going to be able to safely run pump gas (92-93 octane) on this setup? Heads are milled to 59cc which is about 0.045 if im not mistaken. SCR would be right around 11.5:1 which im a little hesitant about.

I'm fine with running a thicker gasket if i have to, just looking for some insight/opinions

dtroike

iTrader: (4)

A thicker head gasket is a terrible way to lower compression. A tight quench area and a little higher compression is usually more detonation friendly. Colder plugs will help a little too. What elevation are you driving it at? Sound like your pushing it but I dont know what stock cam you have. Sound like a good time to upgrade to a little bigger cam. You might double check that compression ratio also, Im not sure but 11.5 sounds with a 59cc sounds a little high to me.

spicebird98

iTrader: (10)

My elevation is usually right around sea level, and I want to stay with the stock cam. Car is an 01 z28

mark21742

If everything else is stock, .045" milled off of the 243's will be fine and should put you closer to 10.7-11:1 scr.

Like said above run a .040" head gasket (I prefer mls) to get your quench right at .035" to help with detonation

PREDATOR-Z

Hi Mark, you better check your math man. .045 milled from 243s is like 7.5 cc. 64.5-7.5 = 57 cc

A stock motor with 57cc and standard gasket is like 11.75:1

His motor with milled 241s will be around 11.4x:1, so use standard gasket, you'll be fine on 93 octane.

mark21742

I miss typed....meant 241's lol. Wouldn't .045" put him closer to 60-61 cc chamber?

The 241's start out at 67cc don't they?

spicebird98

iTrader: (10)

Thanks guys, like i said, im not positive they have been milled exactly .045" but i know its around there. I do know for certain that they are 59cc chambers though

dtroike

iTrader: (4)

it is easy to check the chamber cc's. Buy a syringe from a feed store or vet. get a small piece of plexi glass to put over the chamber and drill a small hole in it on the far side. if you drill it in the middle it is harder to get the air bubble out. line it with a light film of grease and see how many cc's of water it takes to fill it up. I would definetly want to stay under 11:1 with a stock cam at sea level. You may have to change the pistons or heads to get it right. Most people shoot for a quench of about .040 for safety.